Matthew S Cottageville , SC February 14, 2015 Purchased a used microwave to replace one that quit working and it was missing primary grease/air filter screen and secondary charcoal filter was filthy & damaged Took vent hood off to access charcoal filter location, and replaced damaged filter. Then installed primary grease/air filter into it's location. 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes